Machine for digging soil

ABSTRACT

A machine for digging soil is provided, comprising a rotor, spades mounted tiltably on said rotor and retaining members which prevent dug-up clods of being moved further around with said spades instead of being moved to the ground. For preventing damage of machine parts the spades and retaining members are so shaped that in every tilted position of said spades they can pass between said retaining members which are disposed adjacent one another.

United States Patent Vissers 1 June 27, 1972 54 MACHINE FOR DIGGING SOIL 3,012,616 12/1961 Horowitz ..172/94 l 662 088 3/1928 Raussendorff ..172/1l2 X 72 l t. HebertVisse N -V ,Nthl 1 or a ennep e er 3,164,212 l/l965 Vissers ..172 94 [73] Assignee: Lnndbouwerktuigen-en Machinefabriek H. Primary Examiner Robe1-t p lf vlssers Rotterdam Netherlands Assistant Examiner-Stephen C. Pellegrino [22] 0, 1970 Anorney-Imirie, Smiley, Snyder and Butrum 121] Appl. No.: 9,688 [57] ABSTRACT A machine for digging soil is provided, comprising a rotor, [30] Forelgn Application Priority Data spades mounted tiltably on said rotor and retaining members Feb. 13, 1969 Netherlands: ..6902245 which prevent dug-up clods of being moved further around with said spades instead of being moved to the ground [52] US. Cl ..172/39, 172/71, 172/94,

172/1 12 For preventing damage of machine parts the spades and 51 1111.01 ..A01b 33 02, AOlb 33/10 retaining members are so Shaped t11min every tilted position 531 Field 61 Search ..172 94, 39, 71, 112 of said Spades y can p between Said retaining members which are disposed adjacent one another. [56] References Cited 2 Claims, 9 Drawing Figures PATENTEDJUHZ? 1972 3.672.453

SHEET 10F 3 INVENTOR #1 4 554 r r w 3- 5 5/95 1 4 4 M54141 ATTORNEY PATENTEDJum 1972 3.672 ,453

SHEET 2 or 3 /ER EFT l//55 EAS We wfl MM ATTORNEY PATENTED JUN 2 7 m2 SHEET 3 BF 3 FIGS INVENTOR M M @LZZMW ATTORNEY MACHINE FOR DIGGING SOIL The invention relates to a machine for digging soil, comprising a travelling frame, a driven rotor mounted on said frame for rotation around a digging axis, and a number of circular sets of spades, each circular set of spades comprising a retaining member retaining clods dug up by the spades of said circular set, each spade being mounted on said rotor for tilting about a tilting axis transverse of said digging axis and being coupled to a guide member guided by a cam member so shaped that said spade tilts as it rises, said cam member being rotatably mounted concentric with said rotor on said frame and being connected thereto in the operational position by means of a connection comprising a connecting element which is disposed when such connection is overloaded.

A machine ofthe kind specified is known.

To prevent the machine from getting damaged if the tilting movement of the spades is locked, in the prior art machine the cam member is connected to the frame by means of the aforementioned connection, so that the cam member can be uncoupled from the frame and then co-rotate with the rotor when the connection is overloaded. In whatever tilted position they may be, the spades then pass the retaining members which, in the prior art machine, are attached with provision for movement in such a way that they move out of the way of the spades, against the force of a spring, when the spades strike against them. Nevertheless, the shock with which the spades strike against the retaining members may be so great that the spades and/or the machine parts coupled thereto are nevertheless damaged.

The invention has the object to provide a machine of the kind specified and to prevent damage of retaining members, spades and/or machine parts coupled thereto.

To this aim the invention provides a machine of the kind specified in which the spades and retaining members have a shape such that in every tilted position, the spades can pass between the retaining members disposed adjacent one another.

The invention further has the object to provide a machine for digging the soil to an uniform ground surface.

To this aim the invention provides a machine having on its rear a soil guide for guiding dug-up clods to their places in the ground surface.

The invention will be clearly gathered from the following description with reference to the drawings, wherein:

FIG. 1 is a plan view of a preferred embodiment of the machine according to the invention;

FIG. 2 is a side elevation of the machine shown in FIG. 1, showing only one circular set ofspades;

FIG. 3 is a section, taken on the line IlI-III in FIG. 1;

FIG. 4 is a section, to an enlarged scale, taken on the line lV-IV in FIG. 1;

FIG. 5 is a section, taken on the line VV in FIG. 4;

FIG. 6 shows the movement of the cam of a cam member in a prior art machine;

FIG. 7 shows the movement, corresponding to FIG. 6, in the machine illustrated in FIGS. l-5;

FIG. 8 shows the movement, corresponding to FIG. 6, in a variant embodiment of the machine according to the invention, and

FIG. 9 shows the movement, corresponding to FIG. 6, in a second variant of the machine according to the invention.

The machine according to the invention comprises a frame 1 suspended by means of suspension rods 3 from a tractor (not shown). The machine also has a driven tubular rotor 5 which is mounted for rotation in the frame I around a digging axis 4 and to which six circular sets 7 of three spades 6 each are attached. In the frame 1 a camshaft 8 stationary during operation is mounted to pivot around the digging axis 4. The camshaft 8 has a cam member 9 for each circular set 7. Each spade 6 is mounted on the rotor 5, via a pin 10 hearing a pinion 12, to tilt around a tilting axis 11 transverse of the digging axis 4. The pinion 12 engages in a rack 13 mounted with provision for displacement axially of the digging axis 4 in the rotor 5. The rack 13 bears a guide member 14 which engages a groove 15 matching a cam 16 in the cam member 9.

The position of plane 0 of the camshaft 8 can be adjusted in relation to the vertical b through an angle a of, for instance, a maximum of 10 to -10", by a disc 18 coupled to the camshaft 8 engaging an adjusting member 19 adjustably disposed on a rod 20 by means of a screw 21. The rod 20 can be displaced into the frame 1 against the force of a compression spring 22. Whenever, due to abnormal circumstances, the spades 6 exert too much torque on the camshaft 8, the camshaft 8 together with the disc 18 rotates against the action of the compression spring 22, so that the camshaft 8 co-rotates with the rotor 5.

The camshaft 8 is so arranged that spade tilting around the tilting axis 11 starts when the spade 6 passes the plane c. The angular displacement of the rotor is ofiset from the plane 0 in FIGS. 6-9, the spade tilting angle k 0.

Cam 17 (cf. FIG. 6) of the prior art machine is sinusoidal, while the spades tilt through an angle of In contrast, the cam 16 in the machine illustrated in FIGS. 1-5 is not sinusoidal, but as shown in FIG. 7. During an an gular displacement cd of the rotor of 70, spade tilting is very slightly accelerated, and during an angular displacement de of the rotor of 20 it is strongly decelerated. During angular displacement fg of the rotor, the spade 6 is tilted back into its starting position, in which it remains until the following tilting, again beginning at 0. At the place e the spade tilting angle is 92 (instead of 120), and this proved to be adequate. In this way the required acceleration is further reduced during the angular displacement cd of the rotor.

Preferably the cam member has the cam 23 of FIG. 8, which is so shaped that during angular displacement st of the rotor of 15 the acceleration is small, for instance increases gradually, so that the force required for acceleration is still low at that period, where the force on the spade for loosening the clod from the ground is great. Cam 23 is so constructed that acceleration during angular displacement tu of the rotor is constant, the tilting movement is uniform during the angular displacement uv of the rotor, and the tilting is considerably decelerated during angular displacement vw of the rotor. During angular displacement xy of the rotor the spade tilts back again.

The preferred cam 24 (FIG. 9) differs from cam 23 by the feature that with the spade tilting concerning cam 24 is suddenly decelerated. To this end, cam 24 is completely straight over angular displacement nj of the rotor until the maximum tilting angle of 92 is reached, when the tilting suddenly terminates.

A machine having a cam like this can reach a speed of 53 rpm. and a digging speed (arrow 2) of 3 km per hour with a cam of this kind, a working depth of 30 cm and a rotor diameter of l 10 cm. The capacity of the machine according to the invention is substantially greater than that of the prior art machine.

The spades 6 mainly consist of a narrow spade blade 25, a bowed member 26 engaging said blade 25 outside the center thereof.

Each circular set 7 has a matching retaining member 27 so bent as to extend at the inner side of the passing spade blade 25. The arrangement of the retaining members 27 on carrier 28, the shape of the retaining members 27 and the shape of the spades 6 are such (cf. the drawings) that in each of their tilted positions, the spades 6 can pass the retaining members 27. If the spade tilting mechanism becomes accidentally locked, the camshaft 8 co-rotates with the rotor 5, and the spades 6 remain in any tilted position, the spades 6 do not knock against the retaining members 27. The latter can therefore be coupled to the frame 1 in a fixed position, without the interposition of springs or similar means yielding on overloading. The carrier 28 consists of a shaft which is pivotably mounted in the frame 1 and has an arm 29 which can be adjusted to various pivoted positions on the frame 1 by means of a screw 30. The pivoted positions are selected in dependence on the position of the camshaft 8 adjusted by means of adjusting member 19.

Disposed on the rear side of the machine is a soil guide 31 mainly consisting of a shaft 32 pivotably mounted in the frame 1, and a number, for instance two, of guide rods 38 for each circular set 7. The shaft 32 can be adjusted to various positions on the frame 1 by means of an attached arm 34 and ascrew 35. The adjusted position is so chosen that the soil guide 3] guides the dug-up clods hurled backwards by the spades 6 in their flight to the place for which they are intended.

What I claim is:

1. In a machine for digging soil, which machine is of the type comprising a travelling frame, a driven rotor mounted on said frame for rotation about a digging axis, a plurality of sets of spades disposed in longitudinally spaced relation with respect to said digging axis, each set comprising a plurality of arms having inner ends disposed in circumferentially spaced relation and each being connected to said rotor about a tilting axis disposed in a plane transverse to said digging axis, each spade also including a blade fixed to the free end of its associated arm, each blade presenting a cutting edge and an inner face for supporting a clod sliced loose by said cutting edge, cam means concentric with said rotor and normally held in relatively fixed relation to said frame for tilting each spade as it sweeps through a selected are about said digging axis, a retaining member for each set of spades, each said retaining member being fixed to said frame and including a portion disposed inwardly of and in substantially opposed relation to the inner face of each blade as the same reaches its position of substantially maximum tilt during movement through said selected are whereby to assure removal of a clod from such inner face, and overload means for permitting said cam means to rotate with said rotor whereby tilting of said arms is arrested so that at least some of said blades will sweep said selected arcs in untilted condition or in condition of only partial tilting, the improvement wherein:

each arm is of curvilinear form having a free end portion which lies nearly tangential with respect to said selected are;

each said blade being fixed to a free end portion of an associated arm so as to lie also in said nearly tangential relation, and each blade being of selected transverse width; and

said retaining members being spaced apart by amounts greater than said selected transverse width whereby said blades may clear same when said cam means rotates with said rotor as aforesaid.

2. In a digging machine as defined in claim 1 including a soil guide fixed to said frame for guiding dug-up clods, said soil guide being fixed to said frame in trailing relation to said retaining members.

i i l I UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 72 453 Dated Tune 27, 1972 Inventor(s) Herbert Vissers It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

The assignor's name is Landbouwwerktuigenen Machinefabriek H. Vissers N.V.

Signed and sealed this 17th day of October 1972.

(SEAL) Attest:

EDWARD M.FLET.CHER.JR. ROBERT GOITSCHALK Attesting Officer Commissioner of Patents FORM PO-1050 (10-69) USCQMM'DC GO376-P69 U. 5. GOVERNMENT PRINTING OFFICE: I9, 0-356-33l 

1. In a machine for digging soil, which machine is of the type comprising a travelling frame, a driven rotor mounted on said frame for rotation about a digging axis, a plurality of sets of spades disposed in longitudinally spaced relation with respect to said digging axis, each set comprising a plurality of arms having inner ends disposed in circumferentially spaced relation and each being connected to said rotor about a tilting axis disposed in a plane transverse to said digging axis, each spade also including a blade fixed to the free end of its associated arm, each blade presenting a cutting edge and an inner face for supporting a clod sliced loose by said cutting edge, cam means concentric with said rotor and normally held in relatively fixed relation to said frame for tilting each spade as it sweeps through a selected arc about said digging axis, a retaining member for each set of spades, each said retaining member being fixed to said frame and including a portion disposed inwardly of and in substantially opposed relation to the inner face of each blade as the same reaches its position of substantially maximum tilt during movement through said selected arc whereby to assure removal of a clod from such inner face, and overload means for permitting said cam means to rotate with said rotor whereby tilting of said arms is arrested so that at least some of said blades will sweep said selected arcs in untilted condition or in condition of only partial tilting, the improvement wherein: each arm is of curvilinear form having a free end portion which lies nearly tangential with respect to said selected arc; each said blade being fixed to a free end portion of an associated arm so as to lie also in said nearly tangential relation, and each blade being of selected transverse width; and said retaining members being spaced apart by amounts greater than said selected transverse width whereby said blades may clear same when said cam Means rotates with said rotor as aforesaid.
 2. In a digging machine as defined in claim 1 including a soil guide fixed to said frame for guiding dug-up clods, said soil guide being fixed to said frame in trailing relation to said retaining members. 